Remove outdated/unmaintained tutorial (enaqx#753)

Remove 'Learn React by building the Hacker News front page' from Tutorials section

Author: ucg8j

README.md

@@ -141,7 +141,6 @@ A collection of awesome things regarding React ecosystem.
 * [LearnCode React Tutorials](https://www.youtube.com/watch?v=MhkGQAoc7bc&list=PLoYCgNOIyGABj2GQSlDRjgvXtqfDxKm5b)
 * [Thinkster React topics](https://thinkster.io/topics/react)
 * [React tutorial - Cloning Yelp](https://www.fullstackreact.com/articles/react-tutorial-cloning-yelp/)
-* [Learn React by building the Hacker News front page](https://github.com/mking/react-hn)
 * [React.js in patterns](http://krasimirtsonev.com/blog/article/react-js-in-design-patterns)
 * [DIY guide to build your own React](https://engineering.hexacta.com/didact-learning-how-react-works-by-building-it-from-scratch-51007984e5c5)
 * [React cheatsheet](https://devhints.io/react)